Starting Out With Clothes

Hi, I'm a rising sophmore at a T2 (think Dartmouth, Penn CAS etc.) target with a high GPA. I have a part time internship this summer, and will be going through recruiting over the next two years presumably. I'm sure this has been asked before, but is there some sort of reasonable checklist for what clothes I need? Eg. X pairs of dress pants, I have a suit (I'm not sure if I need more than one), any alternations I could reasonably expect to have to do etc. I'm really bad at this stuff... sorry I don't have super specific questions. I'm assuming interviews, info sessions, and coffee chats are pretty much it? Assuming that, what types of clothes would be expected for each of them? Really appreciate the help, I'm just really bad in this area. Also I have a part time internship this summer- they say they don't care what I wear but some people seem to think I should dress formally anyway, any opinions?